SALINITY REDUCTION IN A HYDROPONIC GROWING OF VETIVER GRASS (Vetiveria zizanioides) AND WATER HYACINTH (Eichhornia crassipes)

Abstract

This study aimed to evaluate the ion extraction capacity of two plant species, the vetiver grass (Vetiveria zizanioides) and water hyacinth (Eichhornia crassipes), grown in experimental hydroponic units simulating a Floating System. The hydroponic system used nutrient solutions (A1 and A2) composed of fixed concentrations of macro and micronutrients that had been added to two different concentrations of sodium chloride, resulting in initial electrical conductivities of 1.89 and 5.12 dS m-1, respectively. Physicochemical and quantitative changes in the salinized solutions, as well as visual symptoms of stress were compared in the plants, after experimental treatments. Despite the significant volume reduction in solution A1 (31.5%), the water hyacinth was distinct in its estimated extraction of calcium (52.2%), magnesium (47.6%), sodium (16.5%) and cloride (14.1%) meanwhile, at the same conditions, the vetiver grass and control group had similar performance. The increasing salinity of the A2 solution only promoted significant removal of calcium and magnesium (on average, the water hyacinth reached 27.7 and 26.2% of estimated extraction and the vetiver grass, 13.0 and 11.9%, respectively).

Key Words: nutrient removal, soilless cultivation, vetiver grass, water hyacinth.